Revert of Add OpenGL context to Viewer. (patchset #7 id:120001 of https://codereview.chromium.org/1978573003/ )

Reason for revert:
sk_app/WindowContext.cpp is missing. Need to add file and resubmit.

Original issue's description:
> Add OpenGL context to Viewer.
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1978573003
>
> Committed: https://skia.googlesource.com/skia/+/56a11e4d6f3d436a3c2497c9c9e71a117d78a93f

TBR=brianosman@google.com,bsalomon@google.com,djsollen@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review-Url: https://codereview.chromium.org/1990893002

18 files changed, 80 insertions, 446 deletions

diff --git a/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index 7f18652c2c..d492cdeefe 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -48,15 +48,9 @@ DEFINE_string2(match, m, nullptr,
                "it is skipped unless some list entry starts with ~");
 DEFINE_string(skps, "skps", "Directory to read skps from.");
 
-const char *kBackendTypeStrings[sk_app::Window::kBackendTypeCount] = {
-    " [OpenGL]",
-    " [Vulkan]"
-};
-
 Viewer::Viewer(int argc, char** argv, void* platformData)
     : fCurrentMeasurement(0)
     , fDisplayStats(false)
-    , fBackendType(sk_app::Window::kVulkan_BackendType)
     , fZoomCenterX(0.0f)
     , fZoomCenterY(0.0f)
     , fZoomLevel(0.0f)
@@ -73,7 +67,7 @@ Viewer::Viewer(int argc, char** argv, void* platformData)
     SkCommandLineFlags::Parse(argc, argv);
 
     fWindow = Window::CreateNativeWindow(platformData);
-    fWindow->attach(fBackendType, DisplayParams());
+    fWindow->attach(Window::kVulkan_BackendType, DisplayParams());
 
     // register callbacks
     fCommands.attach(fWindow);
@@ -117,22 +111,6 @@ Viewer::Viewer(int argc, char** argv, void* platformData)
         this->changeZoomLevel(-1.f / 32.f);
         fWindow->inval();
     });
-#ifndef SK_BUILD_FOR_ANDROID
-    fCommands.addCommand('d', "Modes", "Change rendering backend", [this]() {
-        fWindow->detach();
-
-        if (sk_app::Window::kVulkan_BackendType == fBackendType) {
-            fBackendType = sk_app::Window::kNativeGL_BackendType;
-        } 
-        // TODO: get Vulkan -> OpenGL working without swapchain creation failure
-        //else if (sk_app::Window::kNativeGL_BackendType == fBackendType) {
-        //    fBackendType = sk_app::Window::kVulkan_BackendType;
-        //}
-
-        fWindow->attach(fBackendType, DisplayParams());
-        this->updateTitle();
-    });
-#endif
 
     // set up slides
     this->initSlides();
@@ -208,7 +186,6 @@ void Viewer::updateTitle() {
     if (kSRGB_SkColorProfileType == fWindow->getDisplayParams().fProfileType) {
         title.append(" sRGB");
     }
-    title.append(kBackendTypeStrings[fBackendType]);
     fWindow->setTitle(title.c_str());
 }
 
@@ -260,6 +237,7 @@ SkMatrix Viewer::computeMatrix() {
 }
 
 void Viewer::onPaint(SkCanvas* canvas) {
+
     int count = canvas->save();
 
     if (fWindow->supportsContentRect()) {
diff --git a/tools/viewer/Viewer.h b/tools/viewer/Viewer.h
index c785cff78e..13cfada9d2 100644
--- a/tools/viewer/Viewer.h
+++ b/tools/viewer/Viewer.h
@@ -48,8 +48,6 @@ private:
 
     bool                   fDisplayStats;
 
-    sk_app::Window::BackendType fBackendType;
-
     // transform data
     SkScalar               fZoomCenterX;
     SkScalar               fZoomCenterY;
diff --git a/tools/viewer/sk_app/DisplayParams.h b/tools/viewer/sk_app/DisplayParams.h
index 8756ff0aac..836b02ec92 100644
--- a/tools/viewer/sk_app/DisplayParams.h
+++ b/tools/viewer/sk_app/DisplayParams.h
@@ -15,13 +15,11 @@ struct DisplayParams {
     DisplayParams()
         : fColorType(kN32_SkColorType)
         , fProfileType(kLinear_SkColorProfileType)
-        , fMSAASampleCount(0)
-        , fDeepColor(false) {}
+        , fMSAASampleCount(0) {}
 
-    SkColorType        fColorType;
+    SkColorType fColorType;
     SkColorProfileType fProfileType;
-    int                fMSAASampleCount;
-    bool               fDeepColor;
+    int fMSAASampleCount;
 };
 
 }   // namespace sk_app
diff --git a/tools/viewer/sk_app/GLWindowContext.cpp b/tools/viewer/sk_app/GLWindowContext.cpp
deleted file mode 100644
index a491321a2a..0000000000
--- a/tools/viewer/sk_app/GLWindowContext.cpp
+++ /dev/null
@@ -1,112 +0,0 @@
-
-/*
- * Copyright 2015 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "GrContext.h"
-#include "SkSurface.h"
-#include "GLWindowContext.h"
-
-#include "gl/GrGLDefines.h"
-
-#include "gl/GrGLUtil.h"
-#include "GrRenderTarget.h"
-#include "GrContext.h"
-
-#include "SkCanvas.h"
-#include "SkImage_Base.h"
-
-namespace sk_app {
-
-GLWindowContext::GLWindowContext(void* platformData, const DisplayParams& params) 
-    : WindowContext()
-    , fBackendContext(nullptr)
-    , fRenderTarget(nullptr)
-    , fSurface(nullptr) {
-}
-
-void GLWindowContext::initializeContext(void* platformData, const DisplayParams& params) {
-
-    this->onInitializeContext(platformData, params);
-
-    fDisplayParams = params;
-
-    SkAutoTUnref<const GrGLInterface> glInterface;
-    glInterface.reset(GrGLCreateNativeInterface());
-    fBackendContext.reset(GrGLInterfaceRemoveNVPR(glInterface.get()));
-
-    SkASSERT(nullptr == fContext);
-    fContext = GrContext::Create(kOpenGL_GrBackend, (GrBackendContext)fBackendContext.get());
-
-    // We may not have real sRGB support (ANGLE, in particular), so check for
-    // that, and fall back to L32:
-    //
-    // ... and, if we're using a 10-bit/channel FB0, it doesn't do sRGB conversion on write,
-    // so pretend that it's non-sRGB 8888:
-    fPixelConfig = fContext->caps()->srgbSupport() &&
-                   SkColorAndProfileAreGammaCorrect(fDisplayParams.fColorType,
-                                                    fDisplayParams.fProfileType) &&
-                   (fColorBits != 30) ? kSkiaGamma8888_GrPixelConfig : kSkia8888_GrPixelConfig;
-}
-
-void GLWindowContext::destroyContext() {
-    fSurface.reset(nullptr);
-    fRenderTarget.reset(nullptr);
-
-    if (fContext) {
-        // in case we have outstanding refs to this guy (lua?)
-        fContext->abandonContext();
-        fContext->unref();
-        fContext = nullptr;
-    }
-    
-    fBackendContext.reset(nullptr);
-
-    this->onDestroyContext();
-}
-
-sk_sp<SkSurface> GLWindowContext::getBackbufferSurface() {
-    if (nullptr == fSurface) {
-        fActualColorBits = SkTMax(fColorBits, 24);
-
-        if (fContext) {
-            GrBackendRenderTargetDesc desc;
-            desc.fWidth = this->fWidth;
-            desc.fHeight = this->fHeight;
-            desc.fConfig = fPixelConfig;
-            desc.fOrigin = kBottomLeft_GrSurfaceOrigin;
-            desc.fSampleCnt = fSampleCount;
-            desc.fStencilBits = fStencilBits;
-            GrGLint buffer;
-            GR_GL_CALL(fBackendContext, GetIntegerv(GR_GL_FRAMEBUFFER_BINDING, &buffer));
-            desc.fRenderTargetHandle = buffer;
-            fRenderTarget.reset(fContext->textureProvider()->wrapBackendRenderTarget(desc));
-
-            fSurface = this->createRenderSurface(fRenderTarget, fActualColorBits);
-        }
-    }
-
-    return fSurface;
-}
-
-void GLWindowContext::swapBuffers() {
-    this->presentRenderSurface(fSurface, fRenderTarget, fActualColorBits);
-    this->onSwapBuffers();
-}
-
-void GLWindowContext::resize(uint32_t w, uint32_t h) {
-    this->destroyContext();
-
-    this->initializeContext(nullptr, fDisplayParams);
-}
-
-void GLWindowContext::setDisplayParams(const DisplayParams& params) {
-    this->destroyContext();
-
-    this->initializeContext(nullptr, params);
-}
-
-}   //namespace sk_app
diff --git a/tools/viewer/sk_app/GLWindowContext.h b/tools/viewer/sk_app/GLWindowContext.h
deleted file mode 100644
index 6fb5e09889..0000000000
--- a/tools/viewer/sk_app/GLWindowContext.h
+++ /dev/null
@@ -1,63 +0,0 @@
-
-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-#ifndef GLWindowContext_DEFINED
-#define GLWindowContext_DEFINED
-
-
-#include "gl/GrGLInterface.h"
-
-#include "SkRefCnt.h"
-#include "GrRenderTarget.h"
-#include "SkSurface.h"
-
-#include "WindowContext.h"
-
-class GrContext;
-
-namespace sk_app {
-
-class GLWindowContext : public WindowContext {
-public:
-    // This is defined in the platform .cpp file
-    static GLWindowContext* Create(void* platformData, const DisplayParams& params);
-
-    sk_sp<SkSurface> getBackbufferSurface() override;
-
-    bool isValid() override { return SkToBool(fBackendContext.get()); }
-
-    void resize(uint32_t w, uint32_t h) override;
-    void swapBuffers() override;
-
-    void setDisplayParams(const DisplayParams& params) override;
-
-    GrBackendContext getBackendContext() override {
-        return (GrBackendContext) fBackendContext.get();
-    }
-
-protected:
-    GLWindowContext(void*, const DisplayParams&);
-    void initializeContext(void*, const DisplayParams&);
-    virtual void onInitializeContext(void*, const DisplayParams&) = 0;
-    void destroyContext();
-    virtual void onDestroyContext() = 0;
-    virtual void onSwapBuffers() = 0;
-
-    SkAutoTUnref<const GrGLInterface> fBackendContext;
-    sk_sp<GrRenderTarget>             fRenderTarget;
-    sk_sp<SkSurface>                  fSurface;
-
-    // parameters obtained from the native window
-    int                               fSampleCount;
-    int                               fStencilBits;
-    int                               fColorBits;
-    int                               fActualColorBits;
-};
-
-}   // namespace sk_app
-
-#endif
diff --git a/tools/viewer/sk_app/VulkanWindowContext.cpp b/tools/viewer/sk_app/VulkanWindowContext.cpp
index bc200de427..2570e826a3 100644
--- a/tools/viewer/sk_app/VulkanWindowContext.cpp
+++ b/tools/viewer/sk_app/VulkanWindowContext.cpp
@@ -7,7 +7,6 @@
  */
 
 #include "GrContext.h"
-#include "GrRenderTarget.h"
 #include "SkSurface.h"
 #include "VulkanWindowContext.h"
 
@@ -26,12 +25,8 @@
 namespace sk_app {
 
 VulkanWindowContext::VulkanWindowContext(void* platformData, const DisplayParams& params)
-    : WindowContext()
-    , fSurface(VK_NULL_HANDLE)
+    : fSurface(VK_NULL_HANDLE)
     , fSwapchain(VK_NULL_HANDLE)
-    , fImages(nullptr)
-    , fImageLayouts(nullptr)
-    , fSurfaces(nullptr)
     , fCommandPool(VK_NULL_HANDLE)
     , fBackbuffers(nullptr) {
 
@@ -255,7 +250,6 @@ void VulkanWindowContext::createBuffers(VkFormat format) {
 
     // set up initial image layouts and create surfaces
     fImageLayouts = new VkImageLayout[fImageCount];
-    fRenderTargets = new sk_sp<GrRenderTarget>[fImageCount];
     fSurfaces = new sk_sp<SkSurface>[fImageCount];
     for (uint32_t i = 0; i < fImageCount; ++i) {
         fImageLayouts[i] = VK_IMAGE_LAYOUT_UNDEFINED;
@@ -275,9 +269,10 @@ void VulkanWindowContext::createBuffers(VkFormat format) {
         desc.fSampleCnt = 0;
         desc.fStencilBits = 0;
         desc.fRenderTargetHandle = (GrBackendObject) &info;
-        fRenderTargets[i].reset(fContext->textureProvider()->wrapBackendRenderTarget(desc));
-
-        fSurfaces[i] = this->createRenderSurface(fRenderTargets[i], 24);
+        SkSurfaceProps props(GrPixelConfigIsSRGB(fPixelConfig)
+                             ? SkSurfaceProps::kGammaCorrect_Flag : 0,
+                             kUnknown_SkPixelGeometry);
+        fSurfaces[i] = SkSurface::MakeFromBackendRenderTarget(fContext, desc, &props);
     }
 
     // create the command pool for the command buffers
@@ -366,11 +361,8 @@ void VulkanWindowContext::destroyBuffers() {
     delete[] fBackbuffers;
     fBackbuffers = nullptr;
 
-    // Does this actually free the surfaces?
     delete[] fSurfaces;
     fSurfaces = nullptr;
-    delete[] fRenderTargets;
-    fRenderTargets = nullptr;
     delete[] fImageLayouts;
     fImageLayouts = nullptr;
     delete[] fImages;
@@ -406,8 +398,7 @@ void VulkanWindowContext::destroyContext() {
         fSurface = VK_NULL_HANDLE;
     }
 
-    fContext->abandonContext();
-    fContext->unref();
+    delete fContext;
 
     fBackendContext.reset(nullptr);
 }
@@ -428,7 +419,7 @@ VulkanWindowContext::BackbufferInfo* VulkanWindowContext::getAvailableBackbuffer
     return backbuffer;
 }
 
-sk_sp<SkSurface> VulkanWindowContext::getBackbufferSurface() {
+SkSurface* VulkanWindowContext::getBackbufferSurface() {
     BackbufferInfo* backbuffer = this->getAvailableBackbuffer();
     SkASSERT(backbuffer);
 
@@ -519,16 +510,14 @@ sk_sp<SkSurface> VulkanWindowContext::getBackbufferSurface() {
                         QueueSubmit(fBackendContext->fQueue, 1, &submitInfo,
                                     backbuffer->fUsageFences[0]));
 
-    return sk_ref_sp(fSurfaces[backbuffer->fImageIndex].get());
+    return fSurfaces[backbuffer->fImageIndex].get();
 }
 
+
 void VulkanWindowContext::swapBuffers() {
 
     BackbufferInfo* backbuffer = fBackbuffers + fCurrentBackbufferIndex;
 
-    this->presentRenderSurface(fSurfaces[backbuffer->fImageIndex],
-                               fRenderTargets[backbuffer->fImageIndex], 24);
-
     VkImageLayout layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
     VkPipelineStageFlags srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
     VkPipelineStageFlags dstStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
diff --git a/tools/viewer/sk_app/VulkanWindowContext.h b/tools/viewer/sk_app/VulkanWindowContext.h
index 8480a9efa8..ec80a3251d 100644
--- a/tools/viewer/sk_app/VulkanWindowContext.h
+++ b/tools/viewer/sk_app/VulkanWindowContext.h
@@ -13,7 +13,8 @@
 #include "vk/GrVkBackendContext.h"
 #include "WindowContext.h"
 
-class GrRenderTarget;
+class SkSurface;
+class GrContext;
 
 namespace sk_app {
 
@@ -34,15 +35,18 @@ public:
         return ctx;
     }
 
-    sk_sp<SkSurface> getBackbufferSurface() override;
+    SkSurface* getBackbufferSurface() override;
     void swapBuffers() override;
 
+    bool makeCurrent() override { return true; }
+
     bool isValid() override { return SkToBool(fBackendContext.get()); }
 
     void resize(uint32_t w, uint32_t h) override {
         this->createSwapchain(w, h, fDisplayParams);
     }
 
+    const DisplayParams& getDisplayParams() override { return fDisplayParams; }
     void setDisplayParams(const DisplayParams& params) override {
         this->createSwapchain(fWidth, fHeight, params);
     }
@@ -95,21 +99,23 @@ private:
     VkPtr<PFN_vkQueuePresentKHR> fQueuePresentKHR;
     VkPtr<PFN_vkCreateSharedSwapchainsKHR> fCreateSharedSwapchainsKHR;
 
+    GrContext*        fContext;
     VkSurfaceKHR      fSurface;
     VkSwapchainKHR    fSwapchain;
     uint32_t          fPresentQueueIndex;
     VkQueue           fPresentQueue;
     int               fWidth;
     int               fHeight;
-
-    uint32_t               fImageCount;
-    VkImage*               fImages;         // images in the swapchain
-    VkImageLayout*         fImageLayouts;   // layouts of these images when not color attachment
-    sk_sp<GrRenderTarget>* fRenderTargets;  // wrapped rendertargets for those images
-    sk_sp<SkSurface>*      fSurfaces;       // surfaces client renders to (may not be based on rts)
-    VkCommandPool          fCommandPool;
-    BackbufferInfo*        fBackbuffers;
-    uint32_t               fCurrentBackbufferIndex;
+    DisplayParams     fDisplayParams;
+    GrPixelConfig     fPixelConfig;
+
+    uint32_t          fImageCount;
+    VkImage*          fImages;         // images in the swapchain
+    VkImageLayout*    fImageLayouts;   // layouts of these images when not color attachment
+    sk_sp<SkSurface>* fSurfaces;       // wrapped surface for those images
+    VkCommandPool     fCommandPool;
+    BackbufferInfo*   fBackbuffers;
+    uint32_t          fCurrentBackbufferIndex;
 };
 
 }   // namespace sk_app
diff --git a/tools/viewer/sk_app/Window.cpp b/tools/viewer/sk_app/Window.cpp
index 0a7bcf8a70..997500c515 100644
--- a/tools/viewer/sk_app/Window.cpp
+++ b/tools/viewer/sk_app/Window.cpp
@@ -63,7 +63,7 @@ bool Window::onTouch(int owner, InputState state, float x, float y) {
 }
 
 void Window::onPaint() {
-    sk_sp<SkSurface> backbuffer = fWindowContext->getBackbufferSurface();
+    SkSurface* backbuffer = fWindowContext->getBackbufferSurface();
     if (backbuffer) {
         // draw into the canvas of this surface
         SkCanvas* canvas = backbuffer->getCanvas();
@@ -76,6 +76,7 @@ void Window::onPaint() {
     } else {
         // try recreating testcontext
     }
+
 }
 
 void Window::onResize(uint32_t w, uint32_t h) {
diff --git a/tools/viewer/sk_app/Window.h b/tools/viewer/sk_app/Window.h
index 63d5e19e55..72db5cb591 100644
--- a/tools/viewer/sk_app/Window.h
+++ b/tools/viewer/sk_app/Window.h
@@ -33,17 +33,12 @@ public:
     virtual bool supportsContentRect() const { return false; }
     virtual SkRect getContentRect() { return SkRect::MakeEmpty(); }
 
-    enum BackendType {
+    enum BackEndType {
         kNativeGL_BackendType,
-        kVulkan_BackendType,
-
-        kLast_BackendType = kVulkan_BackendType
-    };
-    enum {
-        kBackendTypeCount = kLast_BackendType + 1
+        kVulkan_BackendType
     };
 
-    virtual bool attach(BackendType attachType,  const DisplayParams& params) = 0;
+    virtual bool attach(BackEndType attachType,  const DisplayParams& params) = 0;
     void detach();
 
     // input handling
diff --git a/tools/viewer/sk_app/WindowContext.h b/tools/viewer/sk_app/WindowContext.h
index 1fd921afb2..d48e38e746 100644
--- a/tools/viewer/sk_app/WindowContext.h
+++ b/tools/viewer/sk_app/WindowContext.h
@@ -9,54 +9,30 @@
 
 #include "DisplayParams.h"
 #include "GrTypes.h"
-#include "SkRefCnt.h"
-#include "SkSurfaceProps.h"
 
-class GrContext;
 class SkSurface;
-class GrRenderTarget;
 
 namespace sk_app {
 
+// TODO: fill this out with an interface
 class WindowContext {
 public:
-    WindowContext() : fContext(nullptr)
-                    , fSurfaceProps(SkSurfaceProps::kLegacyFontHost_InitType) {}
-
     virtual ~WindowContext() {}
 
-    virtual sk_sp<SkSurface> getBackbufferSurface() = 0;
+    virtual SkSurface* getBackbufferSurface() = 0;
 
     virtual void swapBuffers() = 0;
 
+    virtual bool makeCurrent() = 0;
+
     virtual bool isValid() = 0;
 
     virtual void resize(uint32_t w, uint32_t h) = 0;
 
-    const DisplayParams& getDisplayParams() { return fDisplayParams; }
+    virtual const DisplayParams& getDisplayParams() = 0;
     virtual void setDisplayParams(const DisplayParams& params) = 0;
 
-    SkSurfaceProps getSurfaceProps() const { return fSurfaceProps; }
-    void setSurfaceProps(const SkSurfaceProps& props) {
-        fSurfaceProps = props;
-    }
-
     virtual GrBackendContext getBackendContext() = 0;
-
-    sk_sp<SkSurface> createRenderSurface(sk_sp<GrRenderTarget>, int colorBits);
-    void presentRenderSurface(sk_sp<SkSurface> renderSurface, sk_sp<GrRenderTarget> rt,
-                              int colorBits);
-
-protected:
-    virtual bool isGpuContext() { return true;  }
-
-    GrContext*        fContext;
-
-    int               fWidth;
-    int               fHeight;
-    DisplayParams     fDisplayParams;
-    GrPixelConfig     fPixelConfig;
-    SkSurfaceProps    fSurfaceProps;
 };
 
 }   // namespace sk_app
diff --git a/tools/viewer/sk_app/android/Window_android.cpp b/tools/viewer/sk_app/android/Window_android.cpp
index 106c40b7b0..9bc79e563e 100644
--- a/tools/viewer/sk_app/android/Window_android.cpp
+++ b/tools/viewer/sk_app/android/Window_android.cpp
@@ -41,7 +41,7 @@ void Window_android::setTitle(const char* title) {
     fSkiaAndroidApp->setTitle(title);
 }
 
-bool Window_android::attach(BackendType attachType, const DisplayParams& params) {
+bool Window_android::attach(BackEndType attachType, const DisplayParams& params) {
     if (kVulkan_BackendType != attachType) {
         return false;
     }
diff --git a/tools/viewer/sk_app/android/Window_android.h b/tools/viewer/sk_app/android/Window_android.h
index c1cd1eb200..2bf7bfeaba 100644
--- a/tools/viewer/sk_app/android/Window_android.h
+++ b/tools/viewer/sk_app/android/Window_android.h
@@ -26,7 +26,7 @@ public:
     void setTitle(const char*) override;
     void show() override {}
 
-    bool attach(BackendType attachType, const DisplayParams& params) override;
+    bool attach(BackEndType attachType, const DisplayParams& params) override;
     void inval() override;
 
     bool scaleContentToFit() const override { return true; }
diff --git a/tools/viewer/sk_app/win/GLWindowContext_win.cpp b/tools/viewer/sk_app/win/GLWindowContext_win.cpp
deleted file mode 100644
index 0694db308f..0000000000
--- a/tools/viewer/sk_app/win/GLWindowContext_win.cpp
+++ /dev/null
@@ -1,110 +0,0 @@
-
-/*
- * Copyright 2015 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "GLWindowContext_win.h"
-
-#include <GL/gl.h>
-
- // windows stuff
-#include "win/SkWGL.h"
-#include "Window_win.h"
-
-namespace sk_app {
-
-// platform-dependent create
-GLWindowContext* GLWindowContext::Create(void* platformData, const DisplayParams& params) {
-    GLWindowContext_win* ctx = new GLWindowContext_win(platformData, params);
-    if (!ctx->isValid()) {
-        delete ctx;
-        return nullptr;
-    }
-    return ctx;
-}
-
-GLWindowContext_win::GLWindowContext_win(void* platformData, const DisplayParams& params)
-    : GLWindowContext(platformData, params)
-    , fHWND(0)
-    , fHGLRC(NULL) {
-
-    // any config code here (particularly for msaa)?
-
-    this->initializeContext(platformData, params);
-}
-
-GLWindowContext_win::~GLWindowContext_win() {
-    this->destroyContext();
-}
-
-void GLWindowContext_win::onInitializeContext(void* platformData, const DisplayParams& params) {
-
-    ContextPlatformData_win* winPlatformData =
-        reinterpret_cast<ContextPlatformData_win*>(platformData);
-
-    if (winPlatformData) {
-        fHWND = winPlatformData->fHWnd;
-    }
-    HDC dc = GetDC(fHWND);
-
-    fHGLRC = SkCreateWGLContext(dc, params.fMSAASampleCount, params.fDeepColor,
-                                kGLPreferCompatibilityProfile_SkWGLContextRequest);
-    if (NULL == fHGLRC) {
-        return;
-    }
-
-    if (wglMakeCurrent(dc, fHGLRC)) {
-        glClearStencil(0);
-        glClearColor(0, 0, 0, 0);
-        glStencilMask(0xffffffff);
-        glClear(GL_STENCIL_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
-
-        // use DescribePixelFormat to get the stencil and color bit depth.
-        int pixelFormat = GetPixelFormat(dc);
-        PIXELFORMATDESCRIPTOR pfd;
-        DescribePixelFormat(dc, pixelFormat, sizeof(pfd), &pfd);
-        fStencilBits = pfd.cStencilBits;
-        // pfd.cColorBits includes alpha, so it will be 32 in 8/8/8/8 and 10/10/10/2
-        fColorBits = pfd.cRedBits + pfd.cGreenBits + pfd.cBlueBits;
-
-        // Get sample count if the MSAA WGL extension is present
-        SkWGLExtensions extensions;
-        if (extensions.hasExtension(dc, "WGL_ARB_multisample")) {
-            static const int kSampleCountAttr = SK_WGL_SAMPLES;
-            extensions.getPixelFormatAttribiv(dc,
-                                              pixelFormat,
-                                              0,
-                                              1,
-                                              &kSampleCountAttr,
-                                              &fSampleCount);
-        } else {
-            fSampleCount = 0;
-        }
-
-        RECT rect;
-        GetClientRect(fHWND, &rect);
-        fWidth = rect.right - rect.left;
-        fHeight = rect.bottom - rect.top;
-        glViewport(0, 0, fWidth, fHeight);
-    }
-}
-
-
-void GLWindowContext_win::onDestroyContext() {
-    wglMakeCurrent(wglGetCurrentDC(), NULL);
-    wglDeleteContext(fHGLRC);
-    fHGLRC = NULL;
-}
-
-
-void GLWindowContext_win::onSwapBuffers() {
-    HDC dc = GetDC((HWND)fHWND);
-    SwapBuffers(dc);
-    ReleaseDC((HWND)fHWND, dc);
-}
-
-
-}   //namespace sk_app
diff --git a/tools/viewer/sk_app/win/GLWindowContext_win.h b/tools/viewer/sk_app/win/GLWindowContext_win.h
deleted file mode 100644
index f30a805e72..0000000000
--- a/tools/viewer/sk_app/win/GLWindowContext_win.h
+++ /dev/null
@@ -1,37 +0,0 @@
-
-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-#ifndef GLWindowContext_win_DEFINED
-#define GLWindowContext_win_DEFINED
-
-#include <windows.h>
-#include "../GLWindowContext.h"
-
-namespace sk_app {
-
-class GLWindowContext_win : public GLWindowContext {
-public:
-    friend GLWindowContext* GLWindowContext::Create(void* platformData, const DisplayParams&);
-
-    ~GLWindowContext_win() override;
-
-    void onSwapBuffers() override;
-
-    void onInitializeContext(void*, const DisplayParams&) override;
-    void onDestroyContext() override;
-
-private:
-    GLWindowContext_win(void*, const DisplayParams&);
-
-    HWND              fHWND;
-    HGLRC             fHGLRC;
-};
-
-
-}
-
-#endif
diff --git a/tools/viewer/sk_app/win/VulkanWindowContext_win.cpp b/tools/viewer/sk_app/win/VulkanWindowContext_win.cpp
index 460dba1da3..05f3bddd31 100644
--- a/tools/viewer/sk_app/win/VulkanWindowContext_win.cpp
+++ b/tools/viewer/sk_app/win/VulkanWindowContext_win.cpp
@@ -6,8 +6,7 @@
  * found in the LICENSE file.
  */
 
-#include "../VulkanWindowContext.h"
-#include "Window_win.h"
+#include "VulkanWindowContext_win.h"
 
 #include "vk/GrVkInterface.h"
 #include "vk/GrVkUtil.h"
diff --git a/tools/viewer/sk_app/win/VulkanWindowContext_win.h b/tools/viewer/sk_app/win/VulkanWindowContext_win.h
new file mode 100644
index 0000000000..e0b5a156f9
--- /dev/null
+++ b/tools/viewer/sk_app/win/VulkanWindowContext_win.h
@@ -0,0 +1,28 @@
+
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef VULKANTESTCONTEXT_WIN_DEFINED
+#define VULKANTESTCONTEXT_WIN_DEFINED
+
+#ifdef SK_VULKAN
+
+#include <windows.h>
+#include "../VulkanWindowContext.h"
+
+namespace sk_app {
+
+// for Windows
+struct ContextPlatformData_win {
+    HINSTANCE fHInstance;
+    HWND      fHWnd;
+};
+
+}
+
+#endif // SK_VULKAN
+
+#endif
diff --git a/tools/viewer/sk_app/win/Window_win.cpp b/tools/viewer/sk_app/win/Window_win.cpp
index 8355c7295a..241a41caba 100644
--- a/tools/viewer/sk_app/win/Window_win.cpp
+++ b/tools/viewer/sk_app/win/Window_win.cpp
@@ -12,8 +12,7 @@
 #include <windowsx.h>
 
 #include "SkUtils.h"
-#include "../GLWindowContext.h"
-#include "../VulkanWindowContext.h"
+#include "VulkanWindowContext_win.h"
 
 namespace sk_app {
 
@@ -265,21 +264,16 @@ void Window_win::show() {
 }
 
 
-bool Window_win::attach(BackendType attachType, const DisplayParams& params) {
+bool Window_win::attach(BackEndType attachType, const DisplayParams& params) {
+    if (kVulkan_BackendType != attachType) {
+        return false;
+    }
+
     ContextPlatformData_win platformData;
     platformData.fHInstance = fHInstance;
     platformData.fHWnd = fHWnd;
 
-    switch (attachType) {
-        case kNativeGL_BackendType:
-        default:
-            fWindowContext = GLWindowContext::Create((void*)&platformData, params);
-            break;
-
-        case kVulkan_BackendType:
-            fWindowContext = VulkanWindowContext::Create((void*)&platformData, params);
-            break;
-    }
+    fWindowContext = VulkanWindowContext::Create((void*)&platformData, params);
 
     return (SkToBool(fWindowContext));
 }
diff --git a/tools/viewer/sk_app/win/Window_win.h b/tools/viewer/sk_app/win/Window_win.h
index 4dd829a914..3501b06ae4 100644
--- a/tools/viewer/sk_app/win/Window_win.h
+++ b/tools/viewer/sk_app/win/Window_win.h
@@ -13,12 +13,6 @@
 
 namespace sk_app {
 
-// for Windows
-struct ContextPlatformData_win {
-    HINSTANCE fHInstance;
-    HWND      fHWnd;
-};
-
 class Window_win : public Window {
 public:
     Window_win() : Window() {}
@@ -29,7 +23,7 @@ public:
     void setTitle(const char*) override;
     void show() override;
 
-    bool attach(BackendType attachType, const DisplayParams& params) override;
+    bool attach(BackEndType attachType, const DisplayParams& params) override;
 
     void inval() override;